Oscar Hammerstein II was born Oscar Greeley Clendenning Hammerstein II on July 12, 1895 in New York City. He was the son of Alice Nimmo and theatrical manager William Hammerstein. His grandfather was the German theatre impresario Oscar Hammerstein I. His father was from a Jewish family, and his mother was the daughter of Scottish and English parents.
Although Hammerstein's father managed the Victoria Theatre for his father and was a producer of vaudeville shows, he was opposed to his son's desire to participate in the arts.
When he was 19, his father died of Bright's disease, June 10, 1914, symptoms of which doctors originally attributed to scarlet fever. On the train trip to the funeral with his brother, he read the headlines in the New York Herald: "Hammerstein's Death a Shock to the Theater Circle. " The New York Times wrote, "Hammerstein, the Barnum of Vaudeville, Dead at Forty. " When he and his brother arrived home, they attended their father's funeral with their grandfather, and more than a thousand others, at Temple Israel in Harlem, and took part in the ceremonies held in the Jewish tradition. Two hours later, "taps was sounded over Broadway, " writes biographer Hugh Fordin.